Displays with features that are changeable in response to the actions of an observer and methods for their manufacture have long been the subject of inventive effort. The usual purpose for making an interactive display is to provide an article having greater sensory appeal than would be created by a non-changeable display. Indeed, a folded greeting card is often designed to deliver an image or text upon being opened that is surprising, humorous, or contrasting when viewed subsequent to the message on the front of the card. Other cards may have a die-cut aperture that enables the person viewing the card to see part or all of an image that is presented on the interior panel. Still other cards may include structures that unfold and expand to create three dimensional forms or scenes.
Substantial creative effort has been directed to developing sophisticated "pop-up" cards, some of which have several components that are cut and folded precisely before being fitted together and glued to the main portion of the card. The assembly precision required to make a pop-up feature operate as intended is a distinct disadvantage. A card with several components that must be cut, folded, interconnected, and affixed to a substrate is certain to require more labor than a product made from a single piece of stock. Compared to a conventional, book-folded card, each of the additional steps required to make a pop-up card is an operation that creates additional losses due to component damage, out-of-tolerance conditions, and increased reject rates. In short, each step in the production process is likely to increase the cost of the finished product, increase the percentage of rejected goods, or both. Although intricate greeting cards and pop-up displays are often quite pleasing, such materials are often intended for display for only a short time. The limited time that such works are displayed imposes a requirement that costs be held as low as possible while still making goods of the desired quality because failure to do so could result in goods that are simply too expensive to be marketed.
Generally, displays with superimposed, spaced-apart image panels, including the present invention, are fabricated from paper; however, any sheet material can be used to make such displays, including, without limitation, vinyl, polyethylene, other polymers, resins, resin-coated paper, treated paper, leather, parchment, foil, leaf, laminae, textile, metal, and wood materials. Displays with superimposed, spaced-apart image panels in the field of the present invention often are purposefully designed to allow them to be mailed readily. Upon opening the display, the recipient may be presented with animation, a changing message, a surprise image, or a dimensionality that is unavailable in conventional greeting cards and similar goods.
Displays of great variety have been used as greeting cards, advertising materials, toys, and the like. Two types of active elements are most commonly used to effect display change: either the "pop-up/pop-out" type or else the "slide/pull-out" type. Many examples of pop-up displays are known, including the fanciful Greeting Card described by Schrager in U.S. Pat. No. 4,763,427. Crowell's Bent Resilient Leaf Spring Pop-up Display Assemblies shown in U.S. Pat. No. 4,774,780 teaches a self-erecting pop-up stationery display that is comprised of a parallelogram or "Z-shaped" resilient leaf spring element bonded to a greeting card or other display medium.
Penick, et al. disclose Pop-ups and Methods of Making in U.S. Pat. No. 4,349,973, but the pop-up element requires the addition of adhesive both in the fabrication of the pop-up portion and also to affix the pop-up element to the card.
In U.S. Pat. No. 4,586,279, for example, Hopkins discloses a Folding Display Assembly that a person can activate to cause animation. The Hopkins apparatus allows a panel that has images of eyes and mouth to move behind a humorous illustration of a humorous face that has cut-outs through which the moving eyes and mouth may be viewed.
Likewise, U.S. Pat. No. 3,946,508 issued to Booras for a Scene-changing Display Card comprised a windowed envelope surrounding a sliding element. A deflectable lower portion of the apparatus is affixed to the sliding element with adhesive. When the lower portion is deflected, the portion of the sliding element that is normally exposed by the envelope window moves out of observation and a different, normally concealed, section of the slide is revealed through the window.
A Folding Card is disclosed by Gasser in U.S. Pat. No. 4,885,859, issued Dec. 12, 1989. Gasser shows a series of windows of decreasing size that are intended to draw the attention of the observer to an advertising slogan printed on the surface exposed by the smallest of the windows. Gasser also forms the folding card from a multiplicity of components. Five pieces of cut sheet material are used to form the simpler of two embodiments Gasser discloses in the patent drawings.
It is also to be noted that many of the earlier devices require cutting complex shapes from the sheet material which makes the manufacture of the display more difficult. For example, the Booras device and the Hopkins device both require an "L" shaped sheet as the starting material. Although other shapes can be used satisfactorily, the starting material for the present invention is preferably rectangular and the cutting needed is generally straight and quite simple, which can reduce material, set-up, tooling, production and re-work costs compared to the displays known in the art.